Invertebrates Surveys

Overview

The invertebrate survey (inverts) protocol is used to quantify the diversity, abundance, and size distribution of motile reef invertebrates at Pristine Seas UVS sites. Divers swim along fixed transects and record invertebrate observations within defined belt widths, using two complementary methods:

  • Standard invertebrate survey — All motile invertebrates within 1 meter of one side of the transect are counted and identified to the lowest possible taxonomic level.
  • Large-scale invertebrate survey — Culturally and fishery important species are measured for size within a wider 4-meter belt on the opposite side of the transect.

This dual protocol captures both fine-scale community composition and large-bodied target species for management applications.

Invertebrate data are organized into three interlinked tables:

  • uvs.inverts_stations — Metadata and ecological summaries for each invertebrate transect station
  • uvs.inverts_counts — Raw counts and size measurements of individual invertebrate taxa
  • uvs.inverts_summary_by_taxa — Station-level summaries by species, including density and average size

All records are linked by ps_station_id, and species are standardized using accepted_aphia_id from taxonomy.inverts.


Tables


Stations (uvs.inverts_stations)

This table contains metadata and summary statistics for each invertebrate survey station. Each row corresponds to a single 50 m transect at a UVS site and includes spatial context, survey effort, and ecological indicators such as species richness and density of target taxa.

Transect structure
  • Standard inverts: 50 m × 1 m belt on one side of the transect
  • Large-scale inverts: 50 m × 4 m belt on the opposite side
Table 1: Schema for uvs.inverts_stations: metadata and summary metrics for motile invertebrate survey stations
Field Type Required Description
ps_station_id STRING true Unique station ID (ps_site_id_depth).
ps_site_id STRING true Foreign key to uvs.sites.
exp_id STRING true Expedition ID (ISO3_YEAR).
method STRING true Survey method (uvs).
protocol STRING true Survey protocol (inverts_motile).
divers STRING true Divers who conducted the invertebrate survey.
region STRING true Region name.
subregion STRING true Subregion name.
locality STRING false Optional local feature (e.g., reef, bay).
latitude FLOAT true Latitude of station (decimal degrees).
longitude FLOAT true Longitude of station (decimal degrees).
date DATE true Date of invertebrate survey.
time TIME true Start time of the survey.
depth_m FLOAT true Average station depth (m).
depth_strata STRING true Depth bin: supershallow, shallow, deep.
habitat STRING true Habitat type.
exposure STRING true Exposure type.
transect_length FLOAT true Length of transect surveyed (typically 50 m).
survey_area_m2 FLOAT true Total area surveyed (transect_length x belt_width).
total_richness INTEGER false Total number of unique invertebrate taxa observed at the station (on-transect only).
total_count INTEGER false Total number of invertebrates recorded.
count_m2 FLOAT false Mean density (individuals/m²).
notes STRING false Optional QA or field notes.

Observations (uvs.inverts_observations)

This table stores raw observations of invertebrates recorded during the surveys. Each row represents a single species recorded on a given transect, and includes taxonomic identity, count, and where applicable, size estimates for large-bodied species.

  • Species are identified using accepted_name and accepted_aphia_id
  • All individuals are counted in the 1 m belt
  • Selected species are measured in the 4 m belt (e.g., giant clams, pearl oysters, conchs, sea cucumbers)
Table 2: Schema for uvs.inverts_observations: raw counts and measurements of motile invertebrates per transect
Field Type Required Description
obs_id STRING true Unique observation ID (e.g., FJI_2025_inv_JSD_0001).
ps_station_id STRING true Foreign key to uvs.inverts_stations.
diver STRING true Name of the diver who recorded the observation.
station_label STRING true Field-assigned stratum label (e.g., shallow, deep).
depth_m FLOAT true Recorded depth (m) at which the transect was conducted.
in_transect BOOLEAN true TRUE if observation was made within the standard 1-m or 4-m survey band; FALSE if incidental or off-transect.
accepted_name STRING true Scientific name (Genus species) of the observed taxon.
accepted_aphia_id INTEGER true WoRMS AphiaID — foreign key to taxonomy.inverts.
functional_group STRING true Functional or cultural group (e.g., sea cucumber, clam, urchin). Assigned post-survey.
count INTEGER true Number of individuals observed for this species.
length_cm FLOAT false Measured length (cm), if applicable for the taxon.
measurement_type STRING false Type of length measured (e.g., shell width, total length). Use standardized vocabulary.
survey_band_m FLOAT true Width of the transect band (m) — typically 1 for general surveys, 4 for large-scale surveys.
count_m2 FLOAT false Density (individuals/m²), standardized by transect area.
notes STRING false Optional comments or QA annotations.

Density by taxa

This table summarizes invertebrate density and size metrics by species at each station. It is the primary analysis-ready table for evaluating community structure and assessing the presence of key indicator species.

Each row is a unique combination of ps_station_id and species, with fields such as:

  • density_m2 — mean individuals per square meter
  • avg_size_cm, min_size_cm, max_size_cm — summary of measured size data
Field Type Required Description
ps_station_id STRING true Unique station ID (ps_site_id_depth).
accepted_name STRING true Scientific name (Genus species) of the observed invertebrate.
accepted_aphia_id INTEGER true WoRMS AphiaID — foreign key to taxonomy.inverts.
functional_group STRING true Functional or cultural grouping (e.g., sea cucumber, clam, urchin).
depth_m FLOAT true Average depth (m) of the station.
depth_strata STRING true Depth bin: supershallow, shallow, or deep.
region STRING true Region name.
subregion STRING true Subregion name.
locality STRING false Optional local feature (e.g., reef, bay, cove).
habitat STRING true Habitat type at the station.
exposure STRING true Exposure type (e.g., windward, leeward, lagoon).
total_count INTEGER false Total number of individuals observed at the station.
total_count_m2 FLOAT false Mean density (individuals/m²), standardized by band width and transect length.
avg_length_cm FLOAT false Weighted mean length (cm), if applicable.
min_length_cm FLOAT false Minimum length (cm) observed at the station.
max_length_cm FLOAT false Maximum length (cm) observed at the station.